


no dawn, no day

by nilchance



Series: ATTL AUs [3]
Category: Undertale (Video Game)
Genre: Body Horror, Emotional/Psychological Abuse, M/M, Mind Rape, Rape, Rape Aftermath, THIS IS NOT CANON FOR ATTL, THIS IS ONLY AN AU, Tentacle Rape, Underfell Papyrus (Undertale), Underfell Sans (Undertale), established kustard, noncon sanster
Language: English
Status: Completed
Published: 2020-06-12
Updated: 2020-06-12
Packaged: 2021-03-03 21:47:59
Rating: Explicit
Warnings: Rape/Non-Con
Chapters: 1
Words: 3,471
Publisher: archiveofourown.org
Story URL: https://archiveofourown.org/works/24682585
Author URL: https://archiveofourown.org/users/nilchance/pseuds/nilchance
Summary: Yet another ATTL AU, in which Gaster is willing to do anything to get his way, no matter how distasteful he finds it. Anything. (Contains graphic non-con.)
Relationships: Papyrus/Sans (Undertale), Sans/Sans (Undertale), W. D. Gaster/Sans
Series: ATTL AUs [3]
Series URL: https://archiveofourown.org/series/1783300
Comments: 60
Kudos: 190





	no dawn, no day

**Author's Note:**

> Like it says on the tag, this fic contains graphic on-screen rape and its immediate aftermath. This is very much not a thing that Gaster would be willing to do or ever intended to do to Sans in ATTL canon, but hey, that's what AUs are for, right? This is set just before where 'heavy with mood' would have been in the timeline.
> 
> This was written for the awesome AshTheRat in exchange for a donation to a bail fund. Thank you so much, my dude, you are a gift and a delight. <3
> 
> detailed content warnings in the endnotes

_I didn't choose this_ , Gaster says.

Sans doesn’t know how long he’s been in the void. How long Gaster has been doing this to him. It could be hours. It could be days. Time runs together as stickily as the goop down the inside of his femurs. No day, no night. It’s forever in here.

 _It disgusts me,_ Gaster says. 

The nest of thick, squirming tendrils (don’t think of tentacles, don’t think of Red, don’t bring that memory here, don’t don’t don’t don’t) crammed into Sans’s pelvis withdraw just a little and then force their way back in. There’s no sound in the void or Sans would be screaming, but his mind supplies a nasty squelch. It helpfully adds in the wet crack of a drumstick being torn off the turkey as his pelvis inevitably breaks because it has to break, it hurts too bad not to break. 

(If it finally breaks, it’ll kill him, and he won’t have to do this anymore.)

(Sorry, Paps.)

It doesn’t break. The tendrils thrust again into him. Sans wouldn’t summon his magic, and so there’s nothing but that sticky black goop coating the tendrils to soften the crushing pressure and friction against his bare pubic arch. His pubic symphysis is pure agony as the cartilage strains to the point of snapping around something way too fucking big.

 _You disgust me,_ Gaster continues. 

Sans knows. He can’t move; he has no choice but to look at Gaster’s face and see the true depths of his contempt. Every time Gaster comes on him, _in_ him, there’s no pleasure on his face. No release. No sadistic triumph. This is just another distasteful but necessary chore that Sans made him do, like wiping marrow off the examination table.

 _But this is the only thing you seem to understand,_ Gaster says. He’s kept himself as far away from Sans as he possibly can while still fucking him, his tendrils at their fullest extension. His hand constructs are what’s holding Sans’s femurs open in their bruising grip, like he can somehow fight his way free in the frozen stillness of the void.

Gaster’s expression tightens like he’s about to sneeze, a simple biological function. Easier to think of it that way. Like Gaster isn’t raping him. Gaster shoves himself even deeper, until the tips of his tendrils brush the inside of Sans’s ribcage. The collar around Sans’s crackles a warning, like every other time Gaster came near his soul, but it’s getting weaker. It barely sparks now. Gaster doesn’t stop. 

Deeper, and Sans’s vision whites out for a second. The only sound in the world is the shrill ringing in his skull. For a moment, he’s back in Snowdin in Edge’s universe, kneeling in the snow, his soul freshly broken under the strain of murdering someone. Maybe he Fell there. He died there before this could happen to him. This isn’t real. This isn’t--

Gaster’s magic touches his soul. 

It isn’t slow. It isn’t gentle. (It isn’t Edge.) Gaster shoves himself in deep and leaves no room for Sans in his own head; it’s only Gaster, and it should only be Gaster because just look at Sans, uselessly leaking fluid, making a mess, achieving nothing with these pointless histrionics. He’s weak. He’s disgusting. How could he ever think he was anything else? 

He failed as a scientist. He watched his own brother die and did nothing. He let the human live despite everything they've done. He whored himself across the underground and didn’t even have the sense to do it for gold, only for scraps of praise and affection, and can’t he see that they were lying when they told him he was worth something without Gaster? Is he too stupid to see that this savage version of himself and his brother only ever wanted him on his knees? Can’t he see that they’re laughing at him behind his back?

(It’s not true. He knows it’s not true.)

But Gaster will make use of him. He’ll make Sans something better. Isn’t that all he’s ever wanted?

(No.)

Yes.

Will he stop struggling now?

(no)

Yes.

 _Good,_ Gaster tells him, a hideous mockery of praise, like Sans can’t feel that his contempt only got stronger. One of his magic hands abandons its post at Sans’s femurs. It curls its cold, spidery fingers around the tips of the tendrils and starts stroking briskly. Gaster tenses. The tendrils shudder and writhe. There is no pleasure in Gaster’s expression, only in the suffocating weight of his mind bearing Sans down and down and down. Satisfaction in a job well done. _Very good._

Gaster’s orgasm is a mechanical thing. Just a body reacting to an overflow of physical input. They share it. Neither of them enjoy it. Something wet hits Sans’s soul and clings there, so cold that it burns. There’s a final harsh jolt around his wrist and then sweet numbness washes over him. His pelvis is screaming white-hot agony around Gaster’s magic, pushed to its absolute limit, but it doesn’t matter. Sans doesn’t matter. It’s only pain.

Gaster pulls out roughly, and it hurts like being cored, but it’s so far away. Light from a distant star, burning out, gone.

The hand construct that was applying manual stimulation to Gaster's magic is now rubbing at the soul, working the fluid deeper into the cracks. The surface is dry, a result of the medication regimen Gaster designed, but it doesn’t seem to be absorbing moisture like it should. If anything, the soul is pushing fluid out with every weak, shuddering beat. Still resisting, even passively. Gaster is annoyed. Sans is--

(glad)

\-- irrelevant. He can’t be anything else. Gaster felt him break. Sans is just another construct now, as useful and empty of will as a magical hand.

The hand construct stops working at the auxiliary soul and releases it. It’s still shedding fluid, but the excess will absorb in time. In this situation, a certain amount of mess is unfortunately inevitable. At least he can simply take the soul, use Sans’s teleportation magic to return home, and leave Sans’s body here in the void. He’s gotten what he requires from it. No need for it to clutter up his lab when Asgore will surely have important work that needs doing. There is a war to start, after all.

Gaster attempts to draw out the auxiliary soul. It resists. The collar around Sans’s wrist continues to keep Gaster from his soul even after it failed to protect Sans from everything else. Gaster’s annoyance deepens, but there is always an adjustment period with new equipment. Most of the intent on the collar has burnt out, and now Sans is no longer here to be protected.

But then Papyrus always was the persistent one, regardless of universal origin. Gaster should thank him, really. If the other Papyrus hadn’t healed Sans’s soul, Gaster wouldn’t have had the strength to project himself out of the void, make contact, and startle Sans into an ill-advised shortcut. He’ll be sure to tell the other Papyrus so when he comes for his brother to repeat the process. That should be amusing.

No matter. If the soul won’t come on command, Gaster will drag it out, loath as he is to actually touch it. He reaches beneath Sans’s ribs for the soul and--

Sans throws every shred that’s left of him into ripping open the void.

It shouldn’t work. It didn’t before. The void strains to hold him, but he keeps shoving. Let him burn himself out. Let him ruin Gaster’s new toy. He doesn’t care, he’d rather be dead than this. He just wants it to stop, he wants out, he wants _Red_ \--

A door opens for him. Someone yanks Sans into the light.

It all happens so fast that the momentum of his panic keeps him moving. He fights wildly against whoever has a hold of him, making up for hours (days) (years) of paralyzed horror. His body is sluggish and nothing below his hips will respond, but he claws and shoves and tries to bite anything that comes within reach. They’re talking in a low, urgent voice but he can’t hear it over the godawful noise someone is making, like a dying animal.

They let him go, and he clumsily drags himself backwards until his back hits something and he can't crawl anymore. Then he just lays there, hyperventilating, trying to make his burning eyes focus after however long he spent in the dark. It turns out the person making that noise is him. He stops, gulping air and shivering like his bones are trying to rearrange themselves. It’s freezing here, cold as the void, but he’s sweating.

Finally, his mind makes sense of the words the blurry shape above him is saying. One word, anyway, thrown frantically into the mix of nonsense syllables like signposts on the road out of hell. 

Sweetheart.

Sans blinks up at the shape and his eyelights finally focus. Black jacket, brown fur on the hood. Eyelights, burning like hellfire. His throat hurts like he screamed it raw, but he rasps, “Red?”

“Yeah, honey,” Red says, desperate relief in his voice. His grin is as strained as Sans's sanity feels. “It’s just me.”

“Oh,” Sans says. His voice jitters with the force of his shivering. Red’s here. He’s in Red’s living room. He called, and Red saved him. “Hi.”

“Hey,” Red says, a veneer of casualness as fake as his gold tooth. “You’re hurt pretty bad. Can I--”

Red’s hand moves, and Sans’s body just overrides him; his mind has absolutely nothing to do with jerking backwards and pressing himself against the wall, as far away from Red as he can get. Louder than he’s ever said anything in his goddamn life, he snarls, “Don’t touch me!”

“Okay,” Red says, raising both hands. There’s a look in his eyes Sans has never seen before, like this is killing him by inches, but his voice stays low and calm. “Sorry. I won’t touch you."

“I’m n-not scared of you, asshole,” Sans says. Feels good to say that. Feels like himself. Feels like he has a self. “I’m disgusting."

Red stares at him with some complicated tangle of emotions Sans can’t hack apart at the moment. His gaze drops to the collar around Sans’s wrist, and that tension winches even tighter before he looks away. He holds out a bundled up blanket he must’ve grabbed off the back of the couch. The motion is slow and deliberate, like Sans is a scared animal. Which he is. “The boss is headed home to fix you up. I’m just gonna put this over you, yeah?”

“Yeah,” Sans says. Something hot-wet wells from his socket and runs down his face. He didn’t know he was crying. He doesn’t feel anything. Shouldn’t he be feeling something right now? Is he doing this wrong? Is there a ‘just got raped a couple minutes ago’ manual he should be reading?

Yeah, he’s definitely in shock.

Red’s as good as his word, draping the blanket over Sans’s shoulders without putting a hand on him. Sans clumsily pulls it tighter around him, painfully aware of the fact that he doesn’t have a stitch of clothing on. Gaster tore them off. Fuck, Sans _liked_ that shirt.

“Did you call Paps?” Sans asks.

“Not yet.” The look in Red’s eyes says he’s not sure that was the right decision. “You want me to?”

“Don’t,” Sans says desperately. “I’m too…”

Finally, Sans looks down at himself. There's a puddle of black spreading beneath him. His pelvic arch is raw and bloody from the friction. What little bone still shows underneath the clinging goop is bruised so dark it’s almost black. His pubic symphysis tore a little. Looking at it makes it real. Makes the pain real, although the shock is mercifully buffering him from the worst of it. His head swims nauseatingly as he rides the thin line of passing out.

“Hey,” Red says sharply, jerking his attention back. Impressively, he manages to look both sympathetic and like Gaster’s gory murder waiting to happen. Gentler, he continues, “You can’t check out on me just yet, sweetheart. Not ‘til the boss comes home. Just keep talking to me.”

They’re laughing at him behind his back. That’s what Gaster said. But Red doesn’t look like he’s laughing. He looks like he might never laugh again. And suddenly Sans is fucking furious, not because Gaster raped him but because of what this is going to do to Red and Edge. Safer to be angry about that. Easier.

(After all, Gaster didn’t want to do it. Sans made him.)

Sans can feel Gaster’s grimy fingerprints inside his head. The rest of it can be washed off, the bruises can be healed, but Gaster got inside what makes him _him_ and rearranged things to his liking.

“He jerked off on my soul,” Sans says. It comes out bizarrely matter-of-fact, and he almost laughs even though nothing is funny right now. “I can’t feel it.”

Red’s eyelights flare like the world burning down. Even though the bitter cold of shock, Sans can feel the heat of that protective anger. He can get warm again, maybe, someday. If he stays close enough to Red. 

And then Red shoves his anger somewhere out of the way. The blowback when he finally lets himself open that door is gonna be truly nasty, but he’s trying not to scare Sans right now. Red’s an asshole, but he’s pretty good at this whole ‘don’t freak out the guy who just got raped’ thing.

Red exhales a long, shaky breath. He’s steady as a rock when he says, “Kinda hard to see through your ribs. Can I look?”

Sans blinks, and another tear runs down his face. He’s a mess of various fluids. All he needs is for somebody to spit or puke on him and he’ll win a prize.

“You shouldn’t get this stuff on you,” Sans says. “It’s--”

Disgusting. Not his word. Gaster’s. But he can’t get it out of his head. He can’t forget seeing himself through Gaster’s eyes, this filthy, stupid thing who didn’t understand until Gaster lowered himself to the level of a rutting animal. 

It’s not Sans’s fault. It was Gaster fucking with his head. He should know better than to buy into it. He _does_ know better. This is bullshit.

(But he felt how much Gaster hated every second of touching him.)

That complicated emotion darkens Red’s expression again. Quietly, he says, “It’ll wash off. But I got gloves if you’re worried about it.”

For soul sex. Sans had been so worried about letting Red see inside his head, and now Gaster’s been there first. Hilarious.

"You have to bring it out,” Sans says. “I don't remember how to do it. Sorry."

“Don’t,” Red says, and the harshness of his voice makes Sans flinch. Stupid. He knows Red won’t hurt him, he’s just _raw_ , abraded to the marrow all over and not just his pelvis. Red winces, seems to struggle for some kind of words, and doesn’t find them. Finally, Red’s fingertips tentatively come to rest on a corner of the blanket Sans is clinging to. It’s the closest he can come to touching Sans right now. It shouldn’t be comforting. It is. “You got nothing to be sorry about.”

“I’ll remember that,” Sans says. He stalls out on whatever he was gonna say for a second, like a car running on fumes. Gets it back, finally, after long enough for Red to retrieve and pull on a latex glove from his inventory. “Y’know. Next time I steal the remote.”

It’s not funny, but Red laughs, even if it’s dangerously shaky. “Yeah, you do that. I’m gonna pull your soul on three, all right? Just tell me if I gotta stop.”

Sans nods jerkily and braces himself to knuckle through the panic because somebody’s gonna have to do this eventually no matter how he feels about it. But his soul feels the familiar grip of Red’s magic and just goes easy. No fear, no last-second resistance as it passes through Sans’s ribcage. It knows Red. It knows that Sans is safe with him, even if Red could never be described as safe.

It hovers there above Red’s palm like a dirty, dying animal. Sans saw it through Gaster’s clinical eyes, but it looks worse like this, in the familiar warmth and light of Red’s living room where he’s seen it cradled gently in his own hands. It’s not an auxiliary soul. It’s not equipment. It’s his, and it’s filthy and broken, and Red might not actually be touching it but his stricken horror is written all over his face so clearly that Sans might as well be in his head.

That giddy, awful laughter threatens again. Sans chokes it back, but there’s still an edge of it in his voice when he says, “That bad, huh?”

Red darts a look at him that says yeah, it’s that fucking bad. Worse, maybe. Then his shoulders set stubbornly, and Red says, “Ain’t nothing that the boss can’t fix.”

Sans can hear it in his voice; Red believes in Edge so hard that reality will damned well bend around his unflinching faith if it knows what’s good for it. If anyone could undo this, it’d be Edge. He won’t stop until it’s healed. Or until they’re all dust. Whichever comes first.

But fixing Sans only made Gaster stronger.

“He’s gonna come for it,” Sans says. The shivering is getting worse. “I dunno if we can stop him now.”

Red doesn’t argue. Hard to do that when the proof of Gaster’s long reach is written all over Sans’s bones. His eyelights burn steadily as he says, “Well, then we’re gonna make him fucking work for it.”

“If he--” The words choke in Sans’s throat. He tries again. “If he gets my soul, the shit he’ll do to you and Edge with it, I can’t-- I need you to--”

He can’t even ask. Red understands anyway. The warmth and life dies in his eyes. He just looks at Sans, and Sans can’t tell what the hell is going on in his head. Only that it hurts so bad Red won’t let him see it. It’s too much to ask.

“Sorry,” Sans says wretchedly. “Never mind, I’ll just--”

“Told you once that if anybody was gonna kill you, it’d be me,” Red says. “If it comes to that, I’ll take care of it. I promise.”

A promise Sans would never have asked for. Red hates promises even more than Sans does. But it’s a weight off Sans’s back, and nobody else could bear it but Red. Red won’t let Gaster take him.

“Thanks,” Sans says. It isn’t enough, but it’s the best he can offer.

“For agreeing to kill you?” Red says dryly. “If I knew you’d be that happy about it, I’d have saved it for Gyftmas.”

Sans chokes out a laugh. A real one, this time, even if it sounds like a sob and hurts like hell. “Mercy killing beats a gift card, I guess.”

Red’s crooked grin widens into something almost sweet. “I guess. You ain’t gonna die on me just yet, though. You want a painkiller?”

Now that Red’s watched over him long enough to be relatively sure adding one more stressor to Sans’s system won’t kill him, that is. 

“Yeah,” Sans sighs. Whatever Gaster did to his soul made the pain not matter, but that’s starting to fade the longer he’s (with Red) out of Gaster’s reach. His pelvis hurts like a motherfucker, and it’s only getting worse. Reluctantly, he adds, “Nothing that’ll knock me out.”

Even if the only thing he wants to do right now is take the strongest drugs Red’s got and pass out so he doesn’t have to be conscious while Edge works on the ruin of his pelvis. (He doesn’t want to have to think about what the fuck he’s going to tell Papyrus.) But there’s stuff he knows now that they need to know too. He can’t let them go in as blind as he did. He won’t let this happen to them.

As Red digs in a bottle of painkillers, Sans hears a familiar engine. A car door slams. Edge is home. In a minute, Edge will see what Gaster did with the collar securely around Sans’s wrist, and it’s going to break his fucking heart.

Sans draws in a shuddering breath. Lets it out. Grabs Red’s hand where it’s resting on the edge of the blanket. He’s filthy and clutching so tight it has to hurt, but Red doesn’t seem to mind. He holds onto Sans like he’s never letting go again. They wait together for the door to open.

It’s gonna be a long night.

**Author's Note:**

> Content warnings: graphic rape and its immediate aftermath; victim blaming from Gaster; emotional manipulation; mind rape; non-consensual soul touching; body horror (void goop and also a mention of Sans's pubic symphysis tearing); discussion between Red and Sans about killing Sans rather than letting Gaster use his soul as a battery


End file.
